This invention relates generally to a method for generating real-time geometric transformation is of 3-D calligraphic images. More specifically it relates to a matrix multiplier system for use with incremental display systems.
In graphic display systems, lines are drawn between data points in a Cartesian coordinate system having a horizontal (X) and vertical (Y) axis (and a Z axis in three-dimensional displays). These data points are represented as coordinate pairs; e.g., x.sub.1, y.sub.1 ; x.sub.2, y.sub.2 ; x.sub.3, y.sub.3 ; etc.
In the field of computer graphics, the ability to generate real-time geometric transformations has many uses. The user can scale a picture up so that details appear more clearly, or down so that more of the picture is visible. It is also useful to be able to rotate or distort an image.
Because of the large number of coordinate pairs required to represent a complex image, there is a need for a transformation device that operates at the drawing rate of the display; and, therefore, does not cause delays. As an example of prior art matrix multipliers, those interested are referred to U.S. Pat. No. b 3,763,365 by Charles L. Seitz. Therein is described a matrix multiplier used in an absolute coordinate system and utilizing homogeneous coordinates.
The present invention, in contrast, is directed toward an incremental rather than an absolute display system and is not complicated by using homogeneous coordinates. The inherent simplicity of the present invention makes it a true real-time system and greatly reduces the number of electronic components that would normally be required. Further, the present invention maintains high accuracy and is able to transform arbitrary shapes as fast as straight lines.